Effects of hyperbaric oxygenation on experimental varicocele on the apoptosis of spermatogenic cell and the expression of hypoxia inducible factor-1α, bax, bcl-2 in adolescent rats

Abstract

Objective To study the effects of hyperbaric oxygenation (HBO) on experimental varicocele on the apoptosis of spermatogenic cell and the expression of hypoxia-inducible factor-1 α( HIF-1α),bax,bcl-2 in adolescent rats. Methods Experimental varicocele models were created by partial ligation of left renal vein in adolescent Sprague-Dawley (SD) male rats. A total of 50 rats were randomly divided into 3 groups, namely sham operation group ( A, n = 10 ) , varicocele group ( B, n = 20 ), and HBO administered after being induced varicocele model ( C, n = 20 ). All the animals were killed 8w after operation. The left testis was collected and the expression of HIF-1α, bcl-2 and bax was detected by immunohistochemical method. The apoptosis of spermatogenic cells was detected by in situ terminal deoxylnucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) technique. Results The expression of HIF-1α and bax in left testis of varicocele group was significantly higher than that of A and C group ( P ＜ 0. 01 ) and positive correlation was found between them ( r = 0. 6751, P ＜ 0. 05 ). The expression of bcl-2 in left testis of varicocele group was significantly lower than that of A and C group ( P ＜ 0.05 ). The incidence of apoptosis was decreased significantly in C group than that in B group (P ＜ 0. 01 ), and the apoptosis number of spermatogenic cells of bilateral testes was decreased. Conclusion HBO can change the expression of HIF-1α, bcl-2and apoptosis associated gene bax in germ cells of experimental varicocele adolescent rats. The apoptosis of spermatogenic cells of bilateral testes caused by left varicocele may be one of the mechanisms of male sterility caused by varicocele. Key words: Varicocele; Seminiferous epithelium; Apoptosis; HIF-1α; bax